The present invention relates to a powdery dispersant suitable for producing hydraulic compositions, such as cement, of excellent fluidity; a process for producing the dispersant; and a hydraulic composition containing the dispersant. More particularly, the invention relates to a powdery dispersant which can be incorporated in advance into a pre-mixed hydraulic composition product; a process for producing the dispersant; and a variety of hydraulic compositions containing the dispersant.
Mechanical strength and durability of hardened cement-containing compositions such as concrete and mortar increase as the water/cement ratio (W/C) decreases, whereas fluidity and workability of the compositions become poor as the W/C ratio decreases. Therefore, a cement dispersant is added to hydraulic compositions in order to assure sufficient fluidity thereof, even though the compositions have a low W/C ratio. Liquid-type dispersants and powdery dispersants predominantly containing a naphthalenesulfonate salt-formalin condensate or a melaminesulfonate salt-formalin condensate are widely employed as the aforementioned dispersants for preparing hydraulic compositions. However, when these dispersants are added to a hydraulic composition, fluidity thereof greatly decreases with elapse of time, thereby disadvantageously lowering workability. Therefore, there have also been employed dispersants containing, as an active ingredient, a polycarboxylate polymer obtained from an acid such as acrylic acid or methacrylic acid.
Since dispersants containing a polycarboxylate polymer are generally in the form of liquid, they cannot be incorporated into a pre-mixed product, which is frequently employed as a plastering material. As compared with powdery dispersants, liquid dispersants require care for transportation and containers, as well as additional treatment of the containers, to thereby increase cost for use of liquid dispersants. In addition, since formalin which is contained in a sulfonate salt-formalin condensate is a hazardous substance, restriction is imposed on handling and use of dispersants containing a formalin condensate.
Thus, pulverization of a dispersant containing a polycarboxylate polymer as a predominant ingredient has been investigated. However, when a powdery dispersant having high solubility to water is produced through a conventional pulverization technique (Japanese Patent Publication (kokoku) No. 7-14829), an insoluble gel is formed during pulverization and the thus-obtained powder has poor characteristics, e.g., poor dispersibility.
Pulverization by means of a spray-drier is also a known technique (Japanese Patent No. 2669761). Since a large amount of inorganic powder must be used in combination in the above technique, the polycarboxylate polymer content in the formed dispersant decreases or the polymer is adsorbed with the inorganic powder, to thereby disadvantageously lower dispersion performance during use in an aqueous solution. Furthermore, when an attempt is made to produce such a dispersant at high content, i.e., approximately 100%, a portion of the product is adsorbed inside a drying tower, thereby lowering production yield thereof. When pulverization of a high-viscoelasticity polymer is attempted, overload of a motor prevents continuous and safe operation. In addition, water removed during a drying step tends to exhibit a high COD, to thereby require additional wastewater treatment.
In view of the foregoing, an object of the present invention is to provide a high-performance powdery dispersant for preparing a high-fluidity hydraulic composition, which dispersant contains a polycarboxylate polymer having a polyalkylene glycol chain. Another object of the invention is to provide a process for effectively producing the dispersant. Still another object is to provide a hydraulic composition containing the dispersant.
The present inventors have conducted earnest studies, and have found that when a reducing agent is added to polycarboxylate polymer having a polyalkylene glycol chain and the resultant mixture is dried and pulverized, there is effectively produced a powdery dispersant which imparts excellent fluidity to a hydraulic composition. The present invention has been accomplished on the basis of this finding.
Accordingly, the present invention provides a process for producing a powdery dispersant for preparing a hydraulic composition, which process comprises adding a reducing agent to a liquid predominantly containing a polycarboxylate polymer having a polyalkylene glycol chain, and drying and pulverizing the resultant mixture. The invention also provides the thus-produced powdery dispersant for preparing a hydraulic composition.
Further, the present invention provides a granular hydraulic composition containing hydraulic material and the aforementioned powdery dispersant for preparing a hydraulic composition.
Further, the present invention provides a cement grout composition containing a binder, an aggregate, an expansion accelerator, and the aforementioned powdery dispersant for preparing a hydraulic composition.
Still further, the present invention provides a self-leveling cement composition containing a binder, a fine aggregate, a defoaming agent, and the aforementioned powdery dispersant for preparing a hydraulic composition.
Still further, the present invention provides a quick-setting grout composition containing a quick-setting cement, gypsum, and the aforementioned powdery dispersant for preparing a hydraulic composition.
Still further, the present invention provides a quick-setting self-leveling composition containing a quick-setting cement, gypsum, a defoaming agent, and the aforementioned powdery dispersant for preparing a hydraulic composition.
Still further, the present invention provides a cement composition which contains the aforementioned powdery dispersant for preparing a hydraulic composition, and a cement predominantly containing calcium aluminates.
No particular limitation is imposed on the polycarboxylate polymer compounds having a polyalkylene glycol chain which may be employed in the present invention, so long as the compounds may be employed as cement dispersants. Examples of such polymer compounds include (A) (meth)acrylate copolymers having a polyalkylene glycol chain and (B) maleate copolymers having a polyalkylene glycol chain (in the case of (B), multi-valent metal salts thereof are excluded). These may be employed singly or in combination of two or more species.
Of copolymers (A), preferable ones are (meth)acrylate copolymers having a polyalkylene glycol chain and a group xe2x80x94COOM (wherein M represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or an organic amine). Of copolymers (B), preferable ones are polyalkylene glycol alkenyl ether-maleic anhydride copolymers (with multi-valent salts thereof being excluded).
In the aforementioned (meth)acrylate copolymers (A), M of the group xe2x80x94COOM is preferably a hydrogen atom; an alkali metal such as sodium or potassium; an alkaline earth metal such as calcium or magnesium; ammonium; or an organic amine.
In the aforementioned copolymers (A) and (B), a polyalkylene glycol chain is preferably a C2-C4 polyalkylene glycol chain, more preferably a chain represented by xe2x80x94O(CH2CH(R3)O)nxe2x80x94. In the chain xe2x80x94O(CH2CH(R3)O)nxe2x80x94, R3 represents a hydrogen atom or a methyl group, and n is 2-200, preferably 5-109, more preferably 20-109, still more preferably 30-109.
Of the aforementioned copolymers (A), preferable ones are acrylate or methacrylate polymer compounds comprising at least two different structural units represented by the following formulas (1) and (2): 
(wherein each of R1, R2, and R3, which may be identical to or different from one another, represents a hydrogen atom or a methyl group; R4 represents a C1-C3 alkyl group; M1 represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or an organic amine; Y representsxe2x80x94CH2Oxe2x80x94 or xe2x80x94COOxe2x80x94; and n is 2-200).
There are two types of structural unit (2); a structural unit in which Y is xe2x80x94CH2Oxe2x80x94 and a structural unit in which Y is xe2x80x94COOxe2x80x94, and either or both of these two units may be present in copolymers (A). In the case in which both are present, either of the structural units may have a mean molecular number (n) of 2-200, and preferably, the amount of structural unit (2) in which Y is xe2x80x94COOxe2x80x94 is 1-30 mol % and the amount of structural unit (2) in which Y is xe2x80x94CH2Oxe2x80x94 is 1-30 mol %.
In the present invention, (meth)acrylate polymer compounds may comprise, in addition to the aforementioned structural units represented by formulas (1) or (2), at least one of structural units represented by the following formulas (3) and (4): 
[wherein R5 represents a hydrogen atom or a methyl group; R6 represents C1-C3 alkyl group; and X represents SO3M2 or xe2x80x94Oxe2x80x94Phxe2x80x94SO3M2 (wherein M2 represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or an organic amine, and Ph represents a phenylene group)].
In addition, preferable (meth)acrylate copolymers (A) include (meth)acrylate copolymers having a number average molecular weight of 2,000-50,000, comprising structural unit (1) represented by formula (1) in an amount of 40-80 mol %, structural unit (2) represented by formula (2) in an amount of 1-45 mol %, structural unit (3) represented by formula (3) in an amount of 2-25 mol %, and structural unit (4) represented by formula (4) in an amount of 3-20 mol %.
In the aforementioned formulas (1) to (4), each of R1 and R2 preferably represents a methyl group. Each of R4 and R6 may be a methyl group, an ethyl group, an n-propyl group, or an i-propyl group. Of these, a methyl group is preferable. M1 is preferably sodium, potassium, calcium, magnesium, or an alkanolamine. Of these, sodium is particularly preferable, in consideration of water-solubility. M2 of a group X may be an alkali metal such as sodium or potassium, an alkaline earth metal such as calcium or magnesium, ammonium, or an organic amine including an alkanolamine such as ethanolamine. The group X is preferably xe2x80x94SO3Na. In formula (2), n is 2-200, preferably 5-109, more preferably 20-109, still more preferably 30-109. Structural unit (1) is preferably present in an amount of 40-80 mol %, more preferably 45-75 mol %. Structural unit (2) is preferably present in an amount of 1-45 mol %, more preferably 3-40 mol %. Structural unit (3) is preferably present in an amount of 2-25 mol %, more preferably 5-20 mol %. Structural unit (4) is preferably present in an amount of 3-20 mol %, more preferably 5-15 mol %. As used herein, mol % of each structural unit is on the basis of the case in which total mol % of structural units (1) to (4) is 100 mol %.
More preferable (meth)acrylate copolymers (A) are (meth)acrylate copolymers having a number average molecular weight of 2,000-50,000, which comprise structural unit (5) represented by the following formula (5) in an amount of 40-70 mol %, structural unit (6) represented by the following formula (6) in an amount of 5-30 mol %, structural unit (7) represented by the following formula (7) in an amount of 1-20 mol %, structural unit (8) represented by the following formula (8) in an amount of 1-30 mol %, and structural unit (9) represented by the following formula (9) in an amount of 1-30 mol %: 
[wherein R7, R8, R10, R11, R13, and R14, which may be identical to or different from one another, each represent a hydrogen atom or a methyl group; R9, R12, and R15 each represent a C1-C3 alkyl group; M3 represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or an organic amine; Z represents xe2x80x94SO3M4 or xe2x80x94Oxe2x80x94Phxe2x80x94SO3M4 (wherein M4 represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or an organic amine, and Ph represents a phenylene group); m is an integer of 2-200; and p is an integer of 2-109].
In the aforementioned formulas (5) to (9), R7, R10, and R13 each preferably represents a methyl group. R9, R12, and R15 may each represent a methyl group, an ethyl group, an n-propyl group, or an i-propyl group. Of these, a methyl group is preferable. M3 and M4 each preferably represent sodium, potassium, calcium, magnesium, or an alkanolamine. Of these, sodium is more preferable. Group Z is preferably xe2x80x94SO3Na. In formula (8), m is 2-200, preferably 5-109, more preferably 20-109, still more preferably 30-109. In formula (9), p is 2-109, preferably 5-50. Structural unit (5) is preferably present in an amount of 40-70 mol %, more preferably 45-65 mol %. Structural unit (6) is preferably present in an amount of 5-30 mol %, more preferably 8-23 mol %. Structural unit (7) is preferably present in an amount of 1-20 mol %, more preferably 1-15 mol %. Structural unit (8) is preferably present in an amount of 1-30 mol %, more preferably 5-25 mol %. Structural unit (9) is preferably present in an amount of 1-30 mol %, more preferably 3-25 mol %. As used herein, mol % of each structural unit is on the basis of the case in which total mol % of structural units (5) to (9) is 100 mol %.
(Meth)acrylate copolymers comprising the aforementioned structural units preferably have a number average molecular weight of 2,000-50,000 (calculated by means of GPC, as reduced to polyethylene glycol), more preferably 3,500-30,000.
Meanwhile, maleate copolymers (B) may be methylpolyethylene glycol vinyl ether-maleic anhydride copolymers, polyethylene glycol allyl ether-maleic anhydride copolymers, methylpolyethylene glycol allyl ether-maleic anhydride copolymers, or methyl methacrylate polyethylene glycol-maleate copolymers. Copolymers (B) preferably have a number average molecular weight (calculated by means of GPC, as reduced to polyethylene glycol) of 3,000-200,000, more preferably 3,000-80,000.
The powdery dispersant for preparing a hydraulic composition of the present invention is produced by adding a reducing agent to a solution predominantly comprising the aforementioned polycarboxylate polymer compound having a polyalkylene glycol chain, and then drying and pulverizing the resultant mixture. The solution predominantly comprising the aforementioned polycarboxylate polymer compound may contain water, a solution of organic solvent, or a dispersing solution.
When a solution predominantly comprising the polycarboxylate polymer compound having a polyalkylene glycol chain is acidic, an aqueous solution of alkali metal or alkaline earth metal such as sodium hydroxide, potassium hydroxide, or calcium hydroxide is preferably added to the polymer solution, adjusting the pH of the solution to 7-9. Since the polymer compound is easily hydrolyzed, the pH of the solution is adjusted in order to prevent deformation or property deterioration of the polymer compound in the solution accompanying hydrolysis of the compound during heating and drying, which are performed later. When the pH of the solution is less than 7, large amounts of reducing agent are required, whereas when the pH is in excess of 9, the polymer compound is easily hydrolyzed or the COD of water that is removed when the solution is dried becomes high, which is unsatisfactory. When the pH of the solution is adjusted to 7-9 in advance, adjusting the pH by the addition of a pH-adjusting agent is unnecessary. Subsequently, a reducing agent is added to the solution having a pH of 7-9. A reducing agent which is added may be any of known ones, so long as it rarely reacts with the polymer compound which is a primary component of the solution. A reducing agent may be a reducing inorganic compound and/or a reducing organic compound.
When a reducing inorganic compound and/or a reducing organic compound are incorporated into a solution predominantly comprising the polycarboxylate polymer compound having a polyalkylene glycol chain, the load imposed on a kneader-mixer is reduced during drying and pulverizing, gel is not produced during drying, and the COD (chemical oxygen demand) of water that is removed is reduced.
Examples of reducing inorganic compounds include sulfite salts, nitrite salts, and thiosulfate salts. These salts are preferably alkali metal salts or alkaline earth metal salts. The reason why gelation is prevented during kneading and mixing in a drying step by the addition of such a reducing inorganic agent has not been elucidated, but it is considered that the reducing inorganic agent may inactivate a radical reaction initiator remaining in the solution comprising the polycarboxylate copolymer. Therefore, the amount of a reducing inorganic agent is determined in accordance with the species of radical reaction initiator remaining in the solution or the amount thereof. Usually, the amount of a reducing inorganic agent is equal to or less than the amount of a radical reaction initiator (as reduced to solid: mol), which is employed for synthesis of the polymer compound. Preferably, the amount of a reducing inorganic agent is equal to or less than the amount of a residual radical reaction initiator (as reduced to solid: mol), or is equal to or more than the amount of the reducing agent such that the reducing agent can inactivate the residual initiator for preventing oxidation by the initiator.
A reducing organic compound is preferably an amine compound, more preferably an alkanolamine. Specific examples include alkanolamines such as triethanolamine, diethanolamine, monoethanolamine, isopropanolamine, and N,N-diethylethanolamine; alkylamines such as sec-butylamine; and diamines such as ethylenediamine. When such a reducing organic compound is added to the solution comprising the polymer compound, the load imposed on a kneader-mixer is considerably reduced, and the COD of water that is removed during drying and pulverizing is reduced to 200 mg/L or less.
The amount of a reducing inorganic compound or a reducing organic compound which is added is preferably 0.01-2.5 wt. % on the basis of the solid content of the polycarboxylate polymer compound, more preferably 0.5-1.5 wt. %. When such a reducing organic compound is added to the solution comprising the polymer compound, the load imposed on a kneader-mixer is reduced during drying and pulverizing, and the COD of water that is removed during drying is reduced, for the reasons described below. The reducing agent may act as a powdering aiding agent, and the agent may facilitate polymerization by the effect of amine at a low temperature in the vicinity of room temperature, resulting in consumption of non-reacted monomer.
After a reducing agent is added to the solution comprising the polymer compound, the resultant mixture is kneaded and mixed. Kneading and mixing are preferably performed at a temperature of about 10-120xc2x0 C., more preferably about 20-100xc2x0 C.
The drying method which may be employed is not particularly limited, so long as a convection-type drying apparatus or a heat-conduction-type drying apparatus is employed. When the solution comprising the polymer compound in an amount of 5-40% is dried, a convection-type drying apparatus such as a spray drier or a flash jet drier is suitably employed. When the solution comprising the polymer compound in an amount of 40% or more or the solution of high viscoelasticity is dried, a heat-conduction-type drying apparatus such as a kneading-mixing drier or a band-type continuous vacuum drier is preferably employed. However, the polycarboxylate polymer compound having a polyalkylene glycol chain may have high viscosity when concentrated, and thus, in view of high efficiency of powdering, the polymer compound is preferably dried and pulverized while it is kneaded and mixed. Kneading and mixing are preferably carried out at a temperature off about 40-120xc2x0 C., more preferably about 60-110xc2x0 C. Kneading and mixing may be carried out in air, but are preferably carried out at reduced pressure or in an atmosphere of inert gas such as nitrogen or argon, in order to prevent deformation of the polymer compound. The polymer compound is preferably dried and pulverized while kneaded and mixed at a power of 0.5 kg/m3/rpm or more, after the compound is concentrated so as to have a hardness of 30xc2x0 or more. Through such a drying procedure, a powdery dispersant can be produced. After completion of drying, the powder may be agglomerated into a floc, but the floc is brittle and thus is easily formed into particles by low pulverizing power.
In the present invention, in order to improve the moisture absorbability or blocking ability of the powdery dispersant or to reduce error in weighing, in addition to the aforementioned essential components, polyalkylene glycols, C8-C22 fatty acids or salts thereof, or inorganic powder may further be incorporated into the powdery dispersant after drying.
Examples of preferable polyalkylene glycols include polyethylene glycol having a molecular weight of 1,000-20,000 and polypropylene glycol having a molecular weight of 2,000-6,000. Of these, polyethylene glycol is more preferable, and polyethylene glycol having a mean molecular weight of 2,000-4,000 is still more preferable.
C8-C22 fatty acids or salts thereof may be saturated or unsaturated, and may have a linear chain or branched chain. Specific examples include caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, undecylenic acid, oleic acid, elaidic acid, cetoleic acid, erucic acid, brassidic acid, and salts thereof. Salts of the aforementioned fatty acids are preferably salts of metals such as sodium, potassium, barium, calcium, zinc, aluminum, and magnesium. Of these, stearic acid or salts thereof are preferable, and calcium stearate is more preferable. The amount of polyalkylene glycols or C8-C22 fatty acids or salts thereof is preferably 0.2-30 wt. % on the basis of the solid content of the polycarboxylate polymer compound having a polyalkylene glycol chain, more preferably 0.5-20 wt. %.
Examples of inorganic powders which may be employed include powder of inorganic salts such as calcium carbonate and calcium silicate; clay mineral powders such as kaolinite and bentonite; and fine powders such as blast furnace slag and fly ash. These inorganic powders are effectively employed in order to improve properties of the powdery dispersant, such as moisture absorbability and blocking ability thereof. In order to pulverize the polycarboxylate polymer compound at high concentration, the amount of inorganic powder which is employed is preferably 0.1-30 wt. % on the basis of the solid content of the compound, more preferably 0.5-10 wt. %.
In consideration of convenience upon use, the pulverized dispersant is preferably prepared so as to have a mean particle size of 5-2,000 xcexcm, more preferably 10-500 xcexcm, through arbitrary crushing and classification methods. However, the produced powdery dispersant is relatively weak against heat, and thus a crushing machine of low heat-storage is preferably employed for crushing the dispersant. Specifically, a pin-type mill is preferably employed. A crushing machine comprising a screen for regulating particle size may be employed, but preferably, crushing and classification are carried out separately, since heat of crushing increases when an uncrushed substance is accumulated in a crushing machine.
The powdery dispersant of the present invention is useful as a dispersant employed in a hydraulic composition such as cement, gypsum, fly ash, blast furnace slag, or silica fumes. Preferably, the powdery dispersant is employed as a cement dispersant.
No particular limitation is imposed on the hydraulic material, such as cement, to which the powdery dispersant may be applied. Examples of such cements include ordinary portland cement, high-early-strength cement, ultra high-early-strength cement, moderate-heat cement, sulfate-resistant cement, and blended cements such as blast furnace-slag cement, fly ash cement, and pozolan cement. In addition, the powdery dispersant may be applied to alumina cement containing large amounts of calcium aluminate, or eco-cement which is produced by firing at least one type of incinerated ashes of city refuse. Furthermore, the dispersant may be applied to spraying cement containing a setting accelerator, or a concrete composition containing blast furnace slag or fly ash as an aggregate component. Examples of hydraulic materials other than cement include gypsum, blast-furnace slag, fly ash, and silica fumes. The amount of the dispersant which is incorporated into a hydraulic material such as cement is appropriately 0.005-5 wt. % on the basis of cement (100 wt. %). Particularly, a granular cement mixture containing the dispersant in an amount of 0.01-3 wt. % is preferable. When the amount of the dispersant which is incorporated is less than 0.005 wt. %, the dispersion effect is reduced. Even when the amount is in excess of 5 wt. %, dispersibility is not further enhanced.
Hydraulic compositions comprising the dispersant of the present invention will next be described.
1. Cement Grout Composition
The cement grout composition of the present invention comprises a binder, an aggregate, an expansion accelerator, and the powdery dispersant for preparing a hydraulic composition of the present invention.
When the amount of the dispersant which is incorporated into the grout composition is very small, the effect of the dispersant is not obtained, whereas the amount is very large, the dispersant may cause retardation of setting of the composition or reduction in strength of the hardened composition. Therefore, the amount of the dispersant is preferably 0.005-5 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.01-3 parts by weight.
Examples of binders which may be employed in the present invention include cements other than quick-setting cements, such as portland cements (e.g., ordinary portland cement, high-early-strength cement, ultra high-early-strength cement, moderate-heat cement, and sulfate-resistant cement), and blended cements (e.g., blast furnace-slag cement, fly ash cement, and pozolan cement).
Examples of aggregates which may be employed in the present invention include river sand, sea sand, land sand, crushed sand, and silica sand. The sand is preferably dried when employed. The aforementioned sand may be employed in combination with fly ash, blast furnace slag, calcium carbonate, or silica fumes. When the grout composition is provided as a mixed grout mortar composition, an aggregate which is incorporated preferably has a size of 5 mm or less and an FM of approximately 1.5-3.0. In the case of a grout mortar composition, when the amount of an aggregate which is incorporated is very small, the hardened composition undergoes excessive shrinkage, whereas when the amount is very large, the fluidity of the composition or the strength of the hardened composition is reduced. Therefore, the amount of an aggregate is preferably 30-300 parts by weight on the basis of 100 parts by weight of a binder, more preferably 60-150 parts by weight.
In the present invention, an expansion accelerator is employed in order to secure adhesion of the grout composition to a structure. Therefore, there may be employed an expansion accelerator which exhibits the effect for reducing shrinkage of the hardened composition and an expansion effect by hydration. Examples of such expansion accelerators include calcium sulfur aluminate inorganic substances such as hauyne, calcium aluminate inorganic substances such as amorphous or crystalline aluminates, lime inorganic substances such as calcium oxide, and metal substances such as aluminum metal powder and iron powder. The amount of an expansion accelerator which is incorporated is as follows. In the case in which a lime expansion accelerator is incorporated, the amount is preferably 0.5-20 parts by weight on the basis of 100 parts by weight of a binder, more preferably 1-10 parts by weight. In the case in which aluminum metal powder is incorporated, the amount is preferably 0.0002-0.01 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.0006-0.008 parts by weight. In the grout composition, more preferably, aluminum metal powder is incorporated in combination with a calcium sulfur aluminate inorganic substance, a calcium aluminate inorganic substance, or a lime inorganic substance, since the effect for reducing shrinkage of the hardened composition is maintained for a prolonged period of time after the composition is produced.
The cement grout composition of the present invention may further contain a thickener.
In the present invention, a thickener is employed in order to prevent separation of materials, and therefore a thickener, which exhibits the effect for imparting viscosity, may be employed. For example, methyl cellulose or polyvinyl alcohol may be employed. The amount of a thickener which is incorporated is preferably 0.001-0.2 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.002-0.05 parts by weight.
If necessary, the cement grout composition of the present invention may contain, in addition to the aforementioned materials, an organic shrinkage-reducing agent. The composition may further contain extenders or admixtures, so long as they do not adversely affect the physical properties of the composition.
The cement grout composition of the present invention is usually provided in a bag-packed form, after the aforementioned materials are mixed. The composition is kneaded with water by use of a mixer at a building site, and then the resultant composition is installed. The type of a mixer which is employed is not particularly limited, and the amount of water which is added to the composition is usually 30-100 parts by weight on the basis of 100 parts by weight of a binder.
2. Self-leveling Cement Composition
The self-leveling cement composition of the present invention comprises a binder, a fine aggregate, a deforming agent, and the powdery dispersant for preparing a hydraulic composition of the present invention.
When the amount of the dispersant which is incorporated into the self-leveling cement composition is very small, the effect of the dispersant is not obtained, whereas the amount is very large, the dispersant may cause retardation of setting of the composition or reduction in strength of the hardened composition. Therefore, the amount of dispersant is preferably 0.005-5 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.01-3 parts by weight.
Examples of binders which are preferably employed in the present invention include cements other than quick-setting cements, such as portland cements (e.g., ordinary portland cement, high-early-strength cement, ultra high-early-strength cement, moderate-heat cement, and sulfate-resistant cement), and blended cements (e.g., blast furnace-slag cement, fly ash cement, and pozolan cement).
Examples of fine aggregates which may be employed in the present invention include river sand, sea sand, land sand, crushed sand, and silica sand. The sand is preferably dried when employed. The aforementioned sand may be employed in combination with fly ash, blast furnace slag, calcium carbonate, or silica fumes. A fine aggregate which is incorporated preferably has a size of 5 mm or less and an FM of approximately 1.5-3.0. In consideration of the fluidity of the composition or the strength of the hardened composition, the amount of an aggregate which is incorporated is preferably 30-300 parts by weight on the basis of 100 parts by weight of a binder, more preferably 60-150 parts by weight.
In the present invention, a deforming agent is employed in order to prevent rising or depression, which is attributed to foam, of a floor in which the composition is employed. A defoaming agent may be a known defoaming agent such as a silicone surfactant or nonionic surfactant. The amount of a defoaming agent which is incorporated is preferably 0.01-0.6 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.05-0.4 parts by weight.
The self-leveling cement composition of the present invention may further contain a thickener. In the present invention, a thickener is employed in order to prevent separation of materials or dry-shrinkage of the hardened composition. For example, methyl cellulose, hydroxyethyl cellulose, or carboxymethyl cellulose may be employed. In consideration of the fluidity and self-leveling ability of the composition, the amount of a thickener which is incorporated is preferably 0.005-0.6 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.01-0.4 parts by weight.
If necessary, the self-leveling cement composition of the present invention may contain, in addition to the aforementioned materials, an expanding agent or an organic shrinkage-reducing agent, in order to prevent cracking of the hardened composition attributed to shrinkage. The composition may further contain extenders or admixtures, so long as they do not adversely affect the physical properties of the composition.
The self-leveling cement composition of the present invention is usually provided in the form of mixture of the aforementioned materials. The composition is kneaded with water by use of a mixer at a building site, and then the resultant composition is installed. The type of a mixer which is employed is not particularly limited, and the amount of water which is added to the composition is usually 30-100 parts by weight on the basis of 100 parts by weight of a binder.
3. Quick-setting Grout Composition
The quick-setting grout composition of the present invention comprises quick-setting cement, gypsum, and the powdery dispersant for preparing a hydraulic composition of the present invention.
When the amount of the dispersant which is incorporated into the grout composition is very small, the effect of the dispersant is not obtained, whereas the amount is very large, the dispersant may cause retardation of setting of the composition or reduction in strength of the hardened composition. Therefore, the amount of dispersant is preferably 0.005-5 parts by weight on the basis of a binder (total of quick-setting cement, other cements, and gypsum) (100 parts by weight), more preferably 0.01-3 parts by weight.
In the present invention, any quick-setting cement may be employed, so long as the cement predominantly contains calcium aluminate. A preferable quick-setting cement contains monocalcium aluminate (CA) as a primary component, and contains Al2O3 in an amount of 65 wt. % or less. A more preferable quick-setting cement contains monocalcium aluminate (CA) as a primary component, and contains Al2O3 in an amount of 30-45 wt. %. In order to attain high fluidity and sufficient quick-setting ability of the composition, in the present invention, quick-setting cement is preferably employed in combination with portland cements (e.g., ordinary portland cement, high-early-strength cement, ultra high-early-strength cement, moderate-heat cement, and sulfate-resistant cement), or blended cements (e.g., blast furnace-slag cement, fly ash cement, and pozolan cement). When quick-setting cement and ordinary portland cement are employed in combination, the incorporation ratio of quick-setting cement to normal cement (by weight) is preferably 1/99 to 90/10, more preferably 3/97 to 50/50.
Gypsum which is employed in the present invention exhibits the effect for enhancing fluidity and quick-setting ability of the composition, and is also expected to exhibit an effect for reducing dry-shrinkage of the hardened composition. In the present invention, any of anhydrous gypsum, hemihydrate gypsum, and dehydrate gypsum may be employed as gypsum, but anhydrous gypsum is most preferable, in consideration of fluidity and quick-setting ability of the composition and of reduction in dry-shrinkage of the hardened composition. The amount of gypsum which is incorporated is preferably 2-150 parts by weight on the basis of quick-setting cement (100 parts by weight), more preferably 10-70 parts by weight.
The quick-setting grout composition of the present invention may further contain a thickener, a setting modifier, an aggregate, and an expansion accelerator.
In the present invention, a thickener is employed in order to prevent separation of materials, and therefore a thicker which exhibits the effect for imparting viscosity may be employed. For example, methyl cellulose or polyvinyl alcohol may be employed. The amount of a thickener which is incorporated is preferably 0.001-0.2 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.002-0.05 parts by weight.
Examples of setting modifiers which are preferably employed include compounds which exhibit setting-acceleration effect; i.e., alkali metal salts, such as lithium carbonate, lithium hydroxide, lithium chloride, lithium nitrate, potassium carbonate, potassium hydroxide, sodium carbonate, and sodium hydroxide. Of these, lithium carbonate is more preferable. In consideration of fluidity of the composition and setting acceleration effect of such a compound, the amount of the compound which is incorporated is preferably 0.005-2 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.05-0.5 parts by weight. Also, examples of setting modifiers which are preferably employed include compounds which exhibit setting-retardation effect; i.e., hydroxycarboxylic acids (including salts therof), such as tartaric acid, citric acid, malic acid, gluconic acid, and salts thereof. Of these, tartaric acid and citric acid are more preferable. In consideration of quick-setting ability of the composition and setting-retardation effect of such a compound, the amount of the compound which is incorporated is preferably 0.005-3 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.03-1 parts by weight.
Examples of aggregates which may be employed in the present invention include river sand, sea sand, land sand, crushed sand, and silica sand. The sand is preferably dried when employed. The aforementioned sand may be employed in combination with fly ash, blast furnace slag, calcium carbonate, or silica fumes. When the grout composition is provided as a mixed grout mortar composition, an aggregate which is incorporated preferably has a size of 5 mm or less and an FM of approximately 1.5-3.0. In the case of a grout mortar composition, the amount of an aggregate which is incorporated is preferably 30-300 parts by weight on the basis of 100 parts by weight of a binder, more preferably 60-150 parts by weight.
In the present invention, an expansion accelerator is employed in order to secure adhesion of the grout composition to a structure. Therefore, there may be employed an expansion accelerator which exhibits an effect for reducing shrinkage of the hardened composition and an expansion effect by hydration. Examples of such expansion accelerators include calcium sulfur aluminate inorganic substances such as hauyne; calcium aluminate inorganic substances such as amorphous or crystalline aluminates; lime inorganic substances such as calcium oxide; and metal substances such as aluminum metal powder and iron powder. The amount of an expansion accelerator which is incorporated is as follows. In the case in which a lime expansion accelerator is incorporated, the amount is preferably 0.5-20 parts by weight on the basis of a binder (100 parts by weigh), more preferably 1-10 parts by weight. In the case in which aluminum metal powder is incorporated, the amount is preferably 0.0002-0.01 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.0006-0.008 parts by weight. In the grout composition, more preferably, aluminum metal powder is incorporated in combination with a calcium sulfur aluminate inorganic substance, a calcium aluminate inorganic substance, or a lime inorganic substance, since the effect for reducing shrinkage of the hardened composition is maintained for a prolonged period of time after the composition is produced.
If necessary, the quick-setting grout composition of the present invention may contain, in addition to the aforementioned materials, a shrinkage-reducing agent. The composition may further contain extenders or admixtures, so long as they do not adversely affect the physical properties of the composition.
The quick-setting grout composition of the present invention is usually provided in the form of mixture of the aforementioned materials. The composition is kneaded with water by use of a mixer at a building site, and then the resultant composition is installed. The type of a mixer which is employed is not particularly limited, and the amount of water which is added to the composition is usually 30-100 parts by weight on the basis of 100 parts by weight of a binder.
4. Quick-setting Self-leveling Composition
The quick-setting self-leveling composition of the present invention comprises quick-setting cement, gypsum, a defoaming agent, and the powdery dispersant for preparing a hydraulic composition of the present invention.
When the amount of the dispersant which is incorporated into the self-leveling composition is very small, the effect of the dispersant is not obtained, whereas the amount is very large, the dispersant may cause retardation of setting of the composition or reduction in strength of the hardened composition. Therefore, the amount of dispersant is preferably 0.005-5 parts by weight on the basis of a binder (total of quick-setting cement, other cements, and gypsum) (100 parts by weight), more preferably 0.01-3 parts by weight.
Quick-setting cement and gypsum employed in the self-leveling composition are the same as those employed in the above-described quick-setting grout composition.
In the present invention, a defoaming agent is employed in order to prevent generation of blisters or depressions, which are attributed to air bubbles, of the floor in which the composition is employed. A defoaming agent may be a known one such as a silicone surfactant or a nonionic surfactant. The amount of a defoaming agent which is incorporated is preferably 0.01-0.6 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.05-0.4 parts by weight.
The quick-setting self-leveling composition of the present invention may further contain a thickener, a setting modifier, and an aggregate.
In the present invention, a thickener is employed in order to prevent separation of materials or dry-shrinkage of the hardened composition. For example, methyl cellulose, hydroxyethyl cellulose, or carboxymethyl cellulose may be employed. In consideration of the fluidity and self-leveling ability of the composition, the amount of a thickener which is incorporated is preferably 0.005-0.6 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.01-0.4 parts by weight.
Examples of setting modifiers which are preferably employed include compounds which exhibits setting-acceleration effect, i.e., alkali metal salts, such as lithium carbonate, lithium hydroxide, lithium chloride, lithium nitrate, potassium carbonate, potassium hydroxide, sodium carbonate, and sodium hydroxide. Of these, lithium carbonate is more preferable. In consideration of fluidity of the composition and setting acceleration effect of such a compound, the amount of the compound which is incorporated is preferably 0.005-2 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.05-0.5 parts by weight. Also, examples of setting modifiers which are preferably employed include compounds which exhibit setting-retardation effect, i.e., hydroxycarboxylic acids (including salts thereof), such as tartaric acid, citric acid, malic acid, gluconic acid, and salts thereof. Of these, tartaric acid and citric acid are more preferable. In consideration of quick-setting ability of the composition and setting-retardation effect of such a compound, the amount of the compound which is incorporated is preferably 0.005-3 parts by weight on the basis of 100 parts by weight of a binder, more preferably 0.03-1 parts by weight.
Examples of fine aggregates which may be employed in the present invention include river sand, sea sand, land sand, crushed sand, and silica sand. The sand is preferably dried when employed. The aforementioned sand may be employed in combination with fly ash, blast furnace slag, calcium carbonate, or silica fume. A fine aggregate which is preferably incorporated has a size of 5 mm or less and an FM of approximately 1.5-3.0. In consideration of the fluidity of the composition or the strength of the hardened composition, the amount of a fine aggregate which is incorporated is preferably 30-300 parts by weight on the basis of 100 parts by weight of a binder, more preferably 60-150 parts by weight.
If necessary, the quick-setting self-leveling composition of the present invention may contain, in addition to the aforementioned materials, an expansive or a shrinkage-reducing agent, in order to prevent cracking of the hardened composition attributed to shrinkage. The composition may further contain extenders or admixtures, so long as they do not adversely affect the physical properties of the composition.
The quick-setting self-leveling composition of the present invention is usually provided in the form of mixture of the aforementioned materials. The composition is kneaded with water by use of a mixer at a building site, and then the resultant composition is installed. The type of a mixer which is employed is not particularly limited, and the amount of water which is added to the composition is usually 30-100 parts by weight on the basis of 100 parts by weight of a binder.
5. (Quick-setting) Cement Composition
The cement composition of the present invention comprises cement predominantly containing calcium aluminates, and the powdery dispersant for preparing hydraulic composition of the present invention.
When the amount of the dispersant which is incorporated into the cement composition is very small, the effect of the dispersant is not obtained, whereas when the amount is very large, the dispersant may cause retardation of setting of the composition or reduction in strength of the hardened composition. Therefore, the amount of dispersant is preferably 0.005-5 parts by weight on the basis of cement predominantly containing calcium aluminates (100 parts by weight), more preferably 0.01-3 parts by weight, still more preferably 0.05-1.5 parts by weight.
When the cement composition is employed as mortar or concrete, river sand, sea sand, land sand, crushed sand, or silica sand may be employed as an aggregate. The sand is preferably dried when employed. The aforementioned sand may be employed in combination with fly ash, blast furnace slag, calcium carbonate, or silica fume. When the cement composition is provided in the form of a premixed mortar composition, an aggregate which is incorporated preferably has a size of 5 mm or less and an FM of approximately 1.5-3.0. In the case of a mortar composition, the amount of an aggregate which is incorporated is preferably 30-300 parts by weight on the basis of a binder (cement predominantly containing calcium aluminates) (100 parts by weight), more preferably 60-150 parts by weight.
The cement composition of the present invention may contain a setting retarder or a setting accelerator, in order to regulating quick-setting ability of the composition. A setting retarder may be any compound which exhibits the effect for retarding hydration of cement predominantly containing calcium aluminates. For example, a compound having a hydroxycarboxyl group, such as citric acid, tartaric acid, or gluconic acid, may be employed. Examples of setting-accelerators include alkali metal salts such as potassium carbonate, sodium carbonate, sodium hydrogencarbonate, lithium carbonate, and sodium aluminate.
If necessary, the cement composition of the present invention may contain, in addition to the aforementioned materials, an expansive, a shrinkage-reducing agent, a thickener, or a setting ability-improving agent (e.g., gypsum). The composition may further contain extenders or admixtures, so long as they do not adversely affect the physical properties of the composition.
The cement composition of the present invention is usually provided in the form of mixture of the aforementioned materials. The composition is kneaded with water by use of a mixer at a building site, and then the resultant composition is installed. The type of a mixer which is employed is not particularly limited, and the amount of water which is added to the composition is usually 30-100 parts by weight on the basis of a binder (cement predominantly containing calcium aluminates) (100 parts by weight).